JP2003516872A - Method for producing polymer or polymer composite polishing pad - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for manufacturing a polishing pad for avoiding a difference in a polishing pad for polishing semiconductor substrates manufactured by different batches. A method of manufacturing a polishing pad (300) used to polish a semiconductor substrate, comprising: transporting a continuous material forming a transported backing layer (302) to a continuous manufacturing station. Supplying the fluid phase polymer composition onto the transported backing layer (302); forming the fluid phase polymer composition into a surface layer of a measured thickness; and transporting the backing layer (302). Curing the above polymer composition in a curing oven to convert the liquid phase polymer composition to a solid phase polymer layer providing a solid phase polishing layer (304) adhered to the transported backing layer (302); A method that includes

Description

Detailed Description of the Invention

The present invention relates to the manufacture of polymer-based polishing pads, especially polishing pads used to polish semiconductor substrates.

US Pat. No. 6,099,954 is a known method of manufacturing a polishing pad for polishing a semiconductor substrate, in which a layer of viscous abrasive is manufactured in-situ. Disclosed is a method comprising the step of solidifying directly onto a portion of a polishing pad. The abrasive is an elastomer or polymer coagulated in situ on a sheet-like underlayer and dried. The abrasive solidifies and adheres to the underlayer. Prior to this invention, batch processing was performed to produce a limited number of polishing pads. The polishing pad produced by one batch process was different from the polishing pad produced by another batch process. What is needed is a manufacturing method that avoids differences in polishing pads manufactured by different batches.

The present invention provides a continuous manufacturing method that eliminates batch processing and reduces the differences between polishing pads manufactured by different batches. A method of manufacturing a polishing pad used for polishing a semiconductor substrate includes a step of transferring a continuous material forming an underlying layer to be transferred through a continuous manufacturing station, and a method of transferring a fluid phase polymer composition. Of the polymer composition on the underlying layer to be transferred, the step of molding the polymer composition on the underlying layer to be formed into a surface layer having an accurately measured thickness, and the curing of the polymer composition on the underlying layer to be transferred. Cured in an oven to attach the polymeric composition to the transferred underlayer,
Converting the polishing pad used to polish the semiconductor substrate into a solid phase polymeric layer that provides a solid phase polishing phase.

[0004]   Hereinafter, embodiments of the present invention will be described as examples with reference to the drawings.

FIG. 3 illustrates an underlayer (3) deposited or otherwise attached to an overlying polishing layer (304).
02) showing part of a polishing pad (300) of the type having. Polishing layer (304)
The polishing pad (300) is known as an abrasive-free pad because it contains no abrasive grains. According to another embodiment, the polishing pad (300) is a fixed-abrasive pad incorporating abrasive particles or particulates (306) dispersed in the polishing layer (304). Abrasive-free pads have abrasive grains or particles (306
) -Free polishing layer (304) as illustrated in FIG.

FIG. 3A shows a polishing pad (30) having an underlayer (302) and a polishing layer (304).
Fig. 7 shows a part of another embodiment of 0). The polishing layer (302) has pores (308) dispersed therein.

FIG. 3B shows a polishing pad (30) having an underlayer (302) and a polishing layer (304).
Fig. 7 shows a part of another embodiment of 0). The polishing layer (302) has microelements dispersed therein in the form of hollow shells (310). Hollow shell (
310) is filled with gas, eg air, at atmospheric pressure or higher pressure. Alternatively, the hollow shell (310) is filled with a known polishing fluid released by fracturing or opening of the hollow shell (310) during a polishing process known as CMP (Chemical Mechanical Planarization). The CMP polishing process uses a polishing pad (300) to polish a semiconductor substrate. Known polishing fluids are polishing pads (300)
And is released at the interface with the semiconductor substrate being polished.

FIG. 1 shows an apparatus (100) for continuously manufacturing a polishing pad (300) in a continuous form. Continuous production replaces batch processing. Continuous manufacturing reduces the differences between different polishing pads (300) caused by batch processing. The device (100) includes a delivery reel (102) containing a spirally wound underlayer (302) in a longitudinally continuous configuration. The underlayer (302) is a non-woven fibrous material, or alternatively, an impermeable membrane, such as a polyester film. The delivery roller (102) is mechanically driven by the drive mechanism (104) to rotate at a controlled speed. The drive mechanism (104) is, for example, a belt (
106) and a motorized pulley (108), or alternatively
For example, it includes a motorized flexible shaft or a motorized gear train.

FIG. 1 shows a continuous underlayer (302) fed onto a continuous conveyor (110), for example a stainless steel belt, which is hung by drive rollers (112) separated by a delivery reel (102). The drive roller (112) is attached to the conveyor (1
The motor is driven at a speed that synchronizes the linear movement of 10) with the linear movement of the continuous underlayer (302). The base layer (302) is transferred to the conveyor (11) by the conveyor (110).
0) to each drive roller (110) and the corresponding idle roller (112a
) Is transferred along the space between. The idle roller (112a) is provided with a base layer () for active tracking control of the conveyor (110) and the base layer (302).
302). The conveyor (110) has a flat area (110a) supported on a flat and horizontal surface of a support (110b), which area is the underlayer (30).
2) is supported horizontally and the underlayer (302) is attached to the continuous manufacturing station (114).
), (122) and (126). Support members (110c) in the form of rollers are arranged along the side edges of the conveyor (110) and the underlayer (302) for active tracking control of the conveyor (110) and the underlayer (302). .

The first manufacturing station (114) includes a storage tank (116) and a nozzle (118) at the outlet of this tank (116). A viscous fluid state polymer composition is supplied to a tank (116) and a continuous underlayer (302) is provided by a nozzle (118).
Is dispensed on top. The nozzle (118) flow rate is controlled by a pump (120) at the outlet of the tank (116). The nozzle (118) has the same width as the width of the continuous underlayer (302) because the underlayer (302) is covered with the polishing layer (304) composed of the fluid-state polymer composition. As the conveyor (110) transports the continuous underlayer (302) through the manufacturing station (114), a continuous fluid phase polishing layer (304) is provided over the underlayer (302).

The second manufacturing station (122) includes a doctor blade (124) located at a precise distance from the continuous underlayer (302) to define a gap therebetween. As the conveyor (110) transfers the continuous underlayer (302) and the fluid phase polishing layer (304) through the doctor blade (124) of the manufacturing station (122), the doctor blade (124) causes the fluid phase polishing layer (304) to move. ) Is continuously molded to the correct thickness.

The third manufacturing station (126) includes a curing oven (128) in the form of a heating tunnel through which the continuous underlayer (302) and the exact thickness of the polishing layer (304) pass. . The oven (128) cures the fluid phase polishing layer (304) into a continuous solid phase polishing layer (304) that adheres to the continuous underlayer (302).
The cure time is controlled by the temperature as it passes through the oven (128) and the transfer rate. The oven (128) is fuel ignited or electrically ignited and uses either radiant heating or forced convection heating or both.

Upon exiting the oven (128), the continuous underlayer (302) is a continuous solid phase polishing layer (
304) to form a continuous polishing pad (300). Continuous polishing pad (3
00) is a take-up reel (130) (FIG. 1) following the manufacturing station (126).
It is spirally wound in A). The take-up reel (130) has a second drive mechanism (1
04). The take-up reel (130) and the second drive mechanism (1
04) constitutes a separate manufacturing station that is selectively located in the manufacturing apparatus (100).

According to the embodiment of the polishing pad (300) disclosed in FIG. 3, a high solids component of a polymer mixture in a viscous fluid state, such as a latex polymer mixture or a polyurethane polymer mixture, is stored in a tank (116). Supplied. According to another embodiment, the polymeric mixture comprises components that are transparent to an electron radiation beam in the wavelength range of about 190 nm to about 3500 nm for optical monitoring and detection. Upon curing in an oven (128), the polymeric mixture solidified into a continuous polishing pad (
300) is formed. Abrasive grains or particles (3) added to the polymer mixture in the fluid state
06) is not included, the continuous polishing pad (300) is an abrasive-free polishing pad (
300).

According to another embodiment, abrasive grains or particles (306) are included as a component in the fluid state polymer mixture. The polymer mixture becomes a matrix mixed with abrasive grains or particles (306). The continuous polishing pad (300) comprises a continuous polishing layer (30
4) Fixed-abrasive polishing pad (30) having abrasive grains or particles (306) dispersed therein.
0).

According to the embodiment of the polishing pad (300) shown in FIG. 3A, entraining ingredients in the form of blowing agents, air insufflation agents, or gases are included in the polymeric mixture that acts as a matrix into which the ingredients are entrained. Upon curing, the blowing agent, air blowing agent, or gas escapes as volatiles, providing the pores (308) dispersed in the continuous polishing layer (304).

According to the embodiment of the polishing pad (300) shown in FIG. 3B, contaminant components in the form of microballoons or polymeric hollow shells (310) are included in the polymeric mixture and dispersed in the continuous polishing layer (304). To do. The shell (310) is gas filled. Alternatively, the shell (310) is worn or fractured or ruptured by the shell (31) when the polishing pad (300) is used in a polishing process known as CMP.
0) is filled with polishing fluid that is dispensed when it opens. Alternatively,
The shell (310) is a water-soluble polymeric microelement that opens by becoming soluble during the polishing process known as CMP.

Prior to the present invention, a batch process for making latex-based polishing pads was to place the high solids latex polymer mix in a mold, place the mold in an oven, and then mold in the oven. In which the pad was cured. The batch process for making the pads has caused pad differences due to the batch and position variations found in the batch process.

FIG. 2 shows a further apparatus (200) for surface conditioning or surface finishing of a continuous polishing pad (300). The apparatus (200) includes a conveyor (110) similar to that shown in FIG. 1 or an extension of the same conveyor (110) shown in FIG. The conveyor (110) of the device (200) has a flat area (11) that supports the drive roller (112) and the continuous polishing pad (300) exiting the oven (126).
0a). The conveyor (110) of the device (200) is connected to the continuous polishing pad (3
00) to one or more manufacturing stations (201), (208) and (2)
12), and subsequent curing in an oven (128), the continuous polishing pad (300) is further processed at these stations. The device (200) has an additional flat support (110) which both operate as shown with reference to FIG.
b) and an additional support member (110c).

The solidified polishing layer (304) is buffed to expose the desired surface finish and flat surface level of the polishing layer (304). Concavities and convexities in the form of grooves or other depressions are machined into the surface of the polishing layer (304). For example, the work station (201) includes a pair of compression molded foil stamping dies having a reciprocating foil stamping die (202) and a stationary die (204) that close against one another during the foil stamping process. The reciprocating die (202) faces the surface of the continuous polishing layer (304). Multiple teeth (206) on the die (202) bite into the surface of the continuous polishing layer (304). The hot stamping process provides a surface finishing process. For example, the teeth (206) pattern a groove on the surface of the polishing layer (304). Further, for example, the teeth (206) open the microballoons or hollow shells (310) present in the polymer mixture at the surface of the continuous polishing layer (304).
The conveyor (110) is intermittently stopped and becomes stationary as the dies (202) and (204) approach each other. Alternatively, the dies (202) and (204) are
As they approach each other, they move in the transfer direction synchronously with the conveyor (110).

Another manufacturing station (208) includes a rotating saw (210) for scoring the surface of the continuous polishing layer (304). The saw (210) is moved along a predetermined path by a known orthogonal motion plotter to cut a predetermined pattern of grooves.

Another manufacturing station (212) applies the surface of the continuous polishing layer (304) to
It includes a rotary milling head (214) for buffing or milling to a flat, flat surface having a desired surface finish that is selectively roughened or smoothed. Furthermore, for example, the milling head (214) opens the microballoons or hollow shells (310) present in the polymer mixture at the surface of the continuous polishing layer (304).

The order of manufacturing stations (202), (210) and (212) may differ from the order shown in FIG. If desired, the manufacturing station (202), (
One or more of 210) and (212) can be excluded. A solid phase continuous polishing pad (300) in which a take-up reel (130) and a second drive mechanism (104) are selectively located at the end of a conveyor (110) in a manufacturing apparatus (200).
A separate manufacturing station for packaging the.

This method is adapted to a liquid-to-solid phase curing system of polymers, which in turn leads to viscous moldable polymer mixtures of the mixture components. Even polymer mixtures without solvent-based intermediate steps, such as injection-molded polymer mixtures, first grind the polymer components to a very small size, disperse the milled components in a concentrated dispersion, dry and then mill. The disclosed method is applied by placing the ingredients in an oven (128) to melt and fuse the milled ingredients.

The raw materials can be mixed in a large homogeneous feed that repeatedly fills the tank (116), thus minimizing differences in the composition and properties of the finished product. The continuity of the method allows for precise control to produce a continuous polishing pad (300) in which a large number of independent polishing pads (300) are cut into a desired area pattern and size. Multiple independent polishing pads (300) have minimal differences in construction and properties.

[Brief description of drawings]

FIG. 1 is a schematic diagram of an apparatus for continuously manufacturing a polishing pad in a continuous form used for polishing a semiconductor substrate.

FIG. 1A   3 is a schematic view of a take-up reel around which a continuous polishing pad is wound.

FIG. 2 is a schematic diagram of an apparatus for continuous conditioning of a continuous polishing pad used to polish a semiconductor substrate.

[Figure 3]   FIG. 2 is a partial cross-sectional view of a polishing pad manufactured by the device shown in FIG. 1.

3A is a view similar to FIG. 3, showing another polishing pad produced by the apparatus shown in FIG.

3B is a view similar to FIG. 3, showing another polishing pad manufactured by the apparatus shown in FIG.

[Explanation of symbols]

100 Polishing pad manufacturing equipment 102 reel, sending reel 104 drive mechanism, second drive mechanism 106 belt 108 motor drive pulley 110 conveyors, continuous conveyors 110a flat section 110b support 110c support member 112 drive roller 112a idle roller 114 Manufacturing Station 116 Storage tank 118 Nozzle at outlet of storage tank 122 Manufacturing Station 124 doctor blade 126 Manufacturing Station 128 curing oven 130 reels, take-up reels 200 Surface conditioning or finishing equipment 201 Manufacturing Station 202 compression molding die, hot stamping die, reciprocating die 204 compression molding die, fixed die 206 teeth 210 rotating saw 212 Manufacturing Station 212 Manufacturing Station 214 rotary milling head 300 polishing pad 302 Backing layer 304 Solid phase polishing layer, continuous polishing layer 306 Abrasive grains, granular materials

[Procedure for Amendment] Submission for translation of Article 34 Amendment of Patent Cooperation Treaty

[Submission date] January 29, 2002 (2002.29)

[Procedure Amendment 1]

[Document name to be amended] Statement

[Name of item to be amended] Claims

[Correction method] Change

[Contents of correction]

[Claims]

Claims (10)

[Claims] 1. A method of manufacturing a polishing pad used to polish a semiconductor substrate, comprising: a continuous manufacturing station (114) (122) (of continuous material forming an underlying layer (302) to be transferred. 126), supplying the fluid phase polymer composition onto the transferred underlayer (302), and the fluid phase polymer composition above the transferred underlayer (302). Is formed into a surface layer (304) having an accurately measured thickness, and the polymer composition on the transferred underlayer (302) is cured in a curing oven to form the polymer composition. Adhered to the transferred underlayer (302),
The solid phase polishing layer (3) of the polishing pad (300) used for polishing a semiconductor substrate.
04) providing a solid phase polymer layer. 2. The method further comprises the step of providing the fluid phase polymer composition as a matrix in which particulates are mixed to provide a solid phase polishing layer (304) of a fixed abrasive polishing pad (300). The method according to item 1. 3. The polishing layer (300) of the polishing pad (300) containing the water-soluble polymer microelements, wherein the fluid-phase polymer composition is supplied as a matrix containing the water-soluble polymer microelements. 304) is further included.
The method of claim 1. 4. The polishing pad (300) containing the polymer microelements, wherein the fluid phase polymer composition is supplied as a matrix containing the polymer microelements having a polymer shell (310). The method of claim 1, further comprising the step of providing a solid phase polishing layer (304). 5. The fluid phase polymer composition is provided as a matrix containing polymer microelements having a polymer shell (310) containing a polishing fluid, the polymer microelements being incorporated. The method of claim 1, further comprising providing a solid phase polishing layer (304) of the polishing pad (300). 6. The step of supplying the fluid phase polymer composition as a matrix containing the abrasive grains (306) to form a solid phase polishing layer of a polishing pad containing the abrasive grains (306). The method of claim 1, further comprising: 7. The method of claim 1, further comprising the step of providing to said fluid phase polymeric component a component that provides a solid phase polishing layer (304) having pores. 8. The method of claim 1, further comprising surface finishing the solid phase polymeric composition and the underlayer (302) with a rotary milling head (214). 9. The method of claim 1, further comprising foil stamping the solid phase polymeric composition and the underlayer (302) between a pair of compression molding dies (202) and (204). . 10. The solid polymer composition in the solid polymer composition by foil stamping the solid polymer composition and the underlayer (302) between a pair of compression molding dies (202) and (204). The method of claim 1, further comprising the step of opening the hollow shell of.